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What is the function of trap flag in 8086 microprocessor?

Question asked by swati verma in #Electronics on Oct 26, 2008
swati verma
swati verma · Oct 26, 2008
Rank D3 - MASTER

what is the function of trap flag in 8086 microprocessor?

Posted in: #Electronics
swati verma
swati verma · Nov 1, 2008
Rank D3 - MASTER
Trap flag when set then single step interrupt will occur after the next instruction.
Trieu Vi Nguyen
Trieu Vi Nguyen · Dec 26, 2012
how to enable Trap flag? which instruction can do that?
rahul69 · Dec 26, 2012
Rank B2 - LEADER
Trieu Vi Nguyen There is no specific instruction to set Trap flag. However, u can set it by changing the Trap Flag Bit of the flags register.
Also, The Trap Flag is mainly used for debugging purposes.
Hope it helps!!!
simplycoder · Dec 30, 2012
Rank B3 - LEADER
Ankita Katdare
Ankita Katdare · Dec 31, 2012
Rank A1 - PRO
More amazingly, this thread has thousands of views. It only goes to say engineers are searching for the basics and CE is providing them the answers. 👍

So, here's my two cents:
Trap Flag is used for on-chip debugging. Debuggers can use it for step-by-step execution of a computer program. If 8086 does a type-1 interrupt, Trap Flag is reset. Therefore, the single-step mode will be disabled during the interrupt-service procedure.
Shanu Verma
Shanu Verma · Oct 5, 2018

will any geek tell me what the hell on earth single step execution means ?

Durgesh Srivastava
Durgesh Srivastava · Jan 30, 2020
Rank C1 - EXPERT

Trap Flags are an important component of microprocessors as they register the outcomes of calculations and actions. Flags are crucial for decision-making in microprocessors.

bill yorke
bill yorke · Jan 30, 2020
Rank C2 - EXPERT

Trap flag is used in trace mode setting, that is, initiating single stepping mode. After every instruction, the microprocessor is interrupted so as to debug the program.

Mohana Chandra
Mohana Chandra · Jan 31, 2020
Rank C1 - EXPERT

Trap flag is a control flag. Trap flag is used for chip-debugging. The functions for which this trap flag used are :

  • To run instruction at a time for debugging.
  • To check whether the memory is available after executtion.
  • To jump to the required instruction,causing effective execution of program.
  • Makes 8086 micro processor to run in single step mode.
Kavya Burramolla
Kavya Burramolla · Feb 1, 2020
Rank C1 - EXPERT

The flag register of 8086 Microprocessor is 16-bit and one bit among 16-bit is used for trap flag.

Trap flag is used for on-chip debugging. When trap flag is set to 1 that puts the microprocessor into single step mode for debugging. In single stepping, the microprocessor executes a instruction and enters into single step Interupt Service Routine(ISR).That is if the trap flag is set, the CPU automatically generates an internal interrupt after each instruction, allowing a program to be inspected as it executes instruction by instruction. And when trap flag is reset, no function is performed.

Venkat Sai Nakkina
Venkat Sai Nakkina · Feb 3, 2020
Rank C3 - EXPERT

This flag is used of we need single-step debugging in our code. If the Trap flag is set, then the execution will be done step by step. Otherwise, the free-running operation will be done.

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